Calibração do balanço de radiação diário através de dados de superfície e de sensores orbitais.

Abstract

Applications of SEBAL/METRIC algorithm for estimation of surface energy balance components have intensifying in Brazilian semi-arid region with objective of water resources management. The use of calibrations proposals for other regions, due to lack of a regional calibration, comes causing errors in the estimate of these components. In this direction, this study it considered the calibration of the biggest possible number of equations to improve the precision of the estimate. Has been used Landsat 5 - TM and data measured in the experiment carried through on a culture of bananas located in the city of Quixeré - CE, Brazil, retrieved in 2005 and 2006 years for application of the algorithm and validation of the results, respectively. Has been proposals calibrations for surface albedo, incoming long-wave radiation, surface temperature and of the sine model for conversion of instantaneous values of net radiation in daily values. The gotten results had been compared with data the measured in the area of study by means of the estimate of the percentile and absolute errors associates. Had been found percentile average error and absolute average error order of 7% e 0,011 for surface albedo, 3% e 12 Wm-2 for incoming long wave radiation e de 8% e 50 Wm-2 for instantaneous net radiation, respectively. The gotten values had been considered satisfactory for the estimation of the components and for the daily net radiation the percentile average error and absolute average error had been found order of only 9,6% and 14,68 Wm-2 for modified sine model and 9,11% and 13,20 Wm-2 for classic SEBAL model, respectively. One concluded that the calibrations proposals had contributed significantly for improvement of the presented method.